For example, a valve apparatus is mounted on a fuel tank of an automobile, which is arranged to prevent fuel leaking out of the fuel tank when the automobile turns or gets inclined.
For example, a float valve apparatus may include a housing, a float valve, an upward urging spring and a support spring (for example, see JP-5265262-B). The housing may include a lower space and an upper space that are divided via a partition wall, a ventilation pipe mounted on an outer wall of the upper space, an opening portion disposed in the partition wall, and a valve seat disposed on a lower face of the opening portion. The float valve may be disposed in the lower space so as to be slidable in the vertical direction. The upward urging spring may be disposed between a lower face of the float valve and a bottom face of the housing, and arranged to urge the float valve toward the opening portion of the partition wall. The support spring may be disposed inside the upward urging spring, and arranged to support the float valve such that the lower face of the float valve is not brought into contact with the bottom face of the housing when the float valve is moved to the lowest position.
In addition, a wall portion standing at a predetermined height may be provided to the peripheral edge portion of the partition wall of the housing. Meanwhile, the ventilation pipe may extend from the outer periphery of the housing in the radial outer direction. The passage on the base end side of the ventilation pipe may extend upward along the axial direction of the housing, and the opening at the upper end of the ventilation pipe may be disposed at a position matching with the upper end of the wall portion at the peripheral edge portion of the partition wall (for example, see FIG. 3 of JP-5265262-B).
In such float valve apparatus, when the float valve is immersed in fuel due to turn or inclination of the vehicle, the float is raised by buoyant force of the float valve or the urging force of the upward urging spring to close the opening portion of the partition wall, which prevents the fuel from flowing into the upper space through the opening portion.
In the above-described configuration, for example, when the fuel strongly sways, the float valve may not be raised in time so that the fuel sometimes flows into the upper space through the opening portion of the partition wall. In this case, the wall portion standing at the peripheral edge portion of the partition wall blocks the opening at the upper end of the ventilation pipe and prevents the fuel from flowing thereinto. However, vigorously flowing into the upper space, the fuel might overflow from the peripheral edge portion of the partition wall of the wall portion, and might flow into the opening at the upper end of the ventilation pipe.